added ability to preserve last update ts for calculated value

application/src/main/java/org/thingsboard/server/controller/CalculatedFieldController.java

@@ -36,6 +36,8 @@ import org.thingsboard.common.util.JacksonUtil;
 import org.thingsboard.script.api.tbel.TbelCfArg;
 import org.thingsboard.script.api.tbel.TbelCfCtx;
 import org.thingsboard.script.api.tbel.TbelCfSingleValueArg;
+import org.thingsboard.script.api.tbel.TbelCfTsDoubleVal;
+import org.thingsboard.script.api.tbel.TbelCfTsRollingArg;
 import org.thingsboard.script.api.tbel.TbelInvokeService;
 import org.thingsboard.server.common.data.EntityType;
 import org.thingsboard.server.common.data.EventInfo;
@@ -242,9 +244,8 @@ public class CalculatedFieldController extends BaseController {
                     ctxAndArgNames.toArray(String[]::new)
             );
 
-
             Object[] args = new Object[ctxAndArgNames.size()];
-            args[0] = new TbelCfCtx(arguments);
+            args[0] = new TbelCfCtx(arguments, getLastUpdateTimestamp(arguments));
             for (int i = 1; i < ctxAndArgNames.size(); i++) {
                 var arg = arguments.get(ctxAndArgNames.get(i));
                 if (arg instanceof TbelCfSingleValueArg svArg) {
@@ -267,6 +268,20 @@ public class CalculatedFieldController extends BaseController {
         return result;
     }
 
+    private long getLastUpdateTimestamp(Map<String, TbelCfArg> arguments) {
+        long lastUpdateTimestamp = -1;
+        for (TbelCfArg entry : arguments.values()) {
+            if (entry instanceof TbelCfSingleValueArg singleValueArg) {
+                long ts = singleValueArg.getTs();
+                lastUpdateTimestamp = Math.max(lastUpdateTimestamp, ts);
+            } else if (entry instanceof TbelCfTsRollingArg tsRollingArg) {
+                long maxTs = tsRollingArg.getValues().stream().mapToLong(TbelCfTsDoubleVal::getTs).max().orElse(-1);
+                lastUpdateTimestamp = Math.max(lastUpdateTimestamp, maxTs);
+            }
+        }
+        return lastUpdateTimestamp;
+    }
+
     private <E extends HasId<I> & HasTenantId, I extends EntityId> void checkReferencedEntities(CalculatedFieldConfiguration calculatedFieldConfig, SecurityUser user) throws ThingsboardException {
         List<EntityId> referencedEntityIds = calculatedFieldConfig.getReferencedEntities();
         for (EntityId referencedEntityId : referencedEntityIds) {

application/src/main/java/org/thingsboard/server/service/cf/ctx/state/BaseCalculatedFieldState.java

@@ -35,13 +35,15 @@ public abstract class BaseCalculatedFieldState implements CalculatedFieldState {
     protected Map<String, ArgumentEntry> arguments;
     protected boolean sizeExceedsLimit;
 
+    protected long lastUpdateTimestamp = -1;
+
     public BaseCalculatedFieldState(List<String> requiredArguments) {
         this.requiredArguments = requiredArguments;
         this.arguments = new HashMap<>();
     }
 
     public BaseCalculatedFieldState() {
-        this(new ArrayList<>(), new HashMap<>(), false);
+        this(new ArrayList<>(), new HashMap<>(), false, -1);
     }
 
     @Override
@@ -59,14 +61,21 @@ public abstract class BaseCalculatedFieldState implements CalculatedFieldState {
             checkArgumentSize(key, newEntry, ctx);
 
             ArgumentEntry existingEntry = arguments.get(key);
+            boolean entryUpdated;
 
             if (existingEntry == null || newEntry.isForceResetPrevious()) {
                 validateNewEntry(newEntry);
                 arguments.put(key, newEntry);
-                stateUpdated = true;
+                entryUpdated = true;
             } else {
-                stateUpdated = existingEntry.updateEntry(newEntry);
+                entryUpdated = existingEntry.updateEntry(newEntry);
             }
+
+            if (entryUpdated) {
+                stateUpdated = true;
+                updateLastUpdateTimestamp(newEntry);
+            }
+
         }
 
         return stateUpdated;
@@ -100,4 +109,17 @@ public abstract class BaseCalculatedFieldState implements CalculatedFieldState {
 
     protected abstract void validateNewEntry(ArgumentEntry newEntry);
 
+    private void updateLastUpdateTimestamp(ArgumentEntry entry) {
+        if (entry instanceof SingleValueArgumentEntry singleValueArgumentEntry) {
+            long ts = singleValueArgumentEntry.getTs();
+            this.lastUpdateTimestamp = Math.max(this.lastUpdateTimestamp, ts);
+        } else if (entry instanceof TsRollingArgumentEntry tsRollingArgumentEntry) {
+            Map.Entry<Long, Double> lastEntry = tsRollingArgumentEntry.getTsRecords().pollLastEntry();
+            if (lastEntry != null) {
+                long ts = lastEntry.getKey();
+                this.lastUpdateTimestamp = Math.max(this.lastUpdateTimestamp, ts);
+            }
+        }
+    }
+
 }

application/src/main/java/org/thingsboard/server/service/cf/ctx/state/CalculatedFieldCtx.java

@@ -28,6 +28,7 @@ import org.thingsboard.server.common.data.cf.configuration.ArgumentType;
 import org.thingsboard.server.common.data.cf.configuration.CalculatedFieldConfiguration;
 import org.thingsboard.server.common.data.cf.configuration.Output;
 import org.thingsboard.server.common.data.cf.configuration.ReferencedEntityKey;
+import org.thingsboard.server.common.data.cf.configuration.SimpleCalculatedFieldConfiguration;
 import org.thingsboard.server.common.data.id.CalculatedFieldId;
 import org.thingsboard.server.common.data.id.EntityId;
 import org.thingsboard.server.common.data.id.TenantId;
@@ -61,6 +62,7 @@ public class CalculatedFieldCtx {
     private final List<String> argNames;
     private Output output;
     private String expression;
+    private boolean preserveLatestTs;
     private TbelInvokeService tbelInvokeService;
     private CalculatedFieldScriptEngine calculatedFieldScriptEngine;
     private ThreadLocal<Expression> customExpression;
@@ -94,6 +96,7 @@ public class CalculatedFieldCtx {
         this.argNames = new ArrayList<>(arguments.keySet());
         this.output = configuration.getOutput();
         this.expression = configuration.getExpression();
+        this.preserveLatestTs = CalculatedFieldType.SIMPLE.equals(calculatedField.getType()) && ((SimpleCalculatedFieldConfiguration) configuration).isPreserveLastUpdateTs();
         this.tbelInvokeService = tbelInvokeService;
 
         this.maxDataPointsPerRollingArg = apiLimitService.getLimit(tenantId, DefaultTenantProfileConfiguration::getMaxDataPointsPerRollingArg);

application/src/main/java/org/thingsboard/server/service/cf/ctx/state/CalculatedFieldState.java

@@ -42,6 +42,8 @@ public interface CalculatedFieldState {
 
     Map<String, ArgumentEntry> getArguments();
 
+    long getLastUpdateTimestamp();
+
     void setRequiredArguments(List<String> requiredArguments);
 
     boolean updateState(CalculatedFieldCtx ctx, Map<String, ArgumentEntry> argumentValues);

application/src/main/java/org/thingsboard/server/service/cf/ctx/state/ScriptCalculatedFieldState.java

@@ -30,7 +30,6 @@ import org.thingsboard.server.common.data.cf.configuration.Output;
 import org.thingsboard.server.service.cf.CalculatedFieldResult;
 
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -67,7 +66,7 @@ public class ScriptCalculatedFieldState extends BaseCalculatedFieldState {
                 args.add(arg);
             }
         }
-        args.set(0, new TbelCfCtx(arguments));
+        args.set(0, new TbelCfCtx(arguments, getLastUpdateTimestamp()));
         ListenableFuture<JsonNode> resultFuture = ctx.getCalculatedFieldScriptEngine().executeJsonAsync(args.toArray());
         Output output = ctx.getOutput();
         return Futures.transform(resultFuture,

application/src/main/java/org/thingsboard/server/service/cf/ctx/state/SimpleCalculatedFieldState.java

@@ -15,6 +15,8 @@
  */
 package org.thingsboard.server.service.cf.ctx.state;
 
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
 import lombok.Data;
@@ -65,19 +67,34 @@ public class SimpleCalculatedFieldState extends BaseCalculatedFieldState {
         double expressionResult = expr.evaluate();
 
         Output output = ctx.getOutput();
-        Object result;
+        Object result = formatResult(expressionResult, output.getDecimalsByDefault());
-        Integer decimals = output.getDecimalsByDefault();
+        JsonNode outputResult = createResultJson(ctx.isPreserveLatestTs(), output.getName(), result);
-        if (decimals != null) {
-            if (decimals.equals(0)) {
-                result = TbUtils.toInt(expressionResult);
-            } else {
-                result = TbUtils.toFixed(expressionResult, decimals);
-            }
-        } else {
-            result = expressionResult;
-        }
 
-        return Futures.immediateFuture(new CalculatedFieldResult(output.getType(), output.getScope(), JacksonUtil.valueToTree(Map.of(output.getName(), result))));
+        return Futures.immediateFuture(new CalculatedFieldResult(output.getType(), output.getScope(), outputResult));
+    }
+
+    private Object formatResult(double expressionResult, Integer decimals) {
+        if (decimals == null) {
+            return expressionResult;
+        }
+        return decimals.equals(0)
+                ? TbUtils.toInt(expressionResult)
+                : TbUtils.toFixed(expressionResult, decimals);
+    }
+
+    private JsonNode createResultJson(boolean preserveLatestTs, String outputName, Object result) {
+        ObjectNode valuesNode = JacksonUtil.newObjectNode();
+        valuesNode.set(outputName, JacksonUtil.valueToTree(result));
+
+        long lastTimestamp = getLastUpdateTimestamp();
+        if (preserveLatestTs && lastTimestamp != -1) {
+            ObjectNode resultNode = JacksonUtil.newObjectNode();
+            resultNode.put("ts", lastTimestamp);
+            resultNode.set("values", valuesNode);
+            return resultNode;
+        } else {
+            return valuesNode;
+        }
     }
 
 }

common/data/src/main/java/org/thingsboard/server/common/data/cf/configuration/SimpleCalculatedFieldConfiguration.java

@@ -23,6 +23,8 @@ import org.thingsboard.server.common.data.cf.CalculatedFieldType;
 @EqualsAndHashCode(callSuper = true)
 public class SimpleCalculatedFieldConfiguration extends BaseCalculatedFieldConfiguration implements CalculatedFieldConfiguration {
 
+    private boolean preserveLastUpdateTs;
+
     @Override
     public CalculatedFieldType getType() {
         return CalculatedFieldType.SIMPLE;

common/script/script-api/src/main/java/org/thingsboard/script/api/tbel/TbelCfCtx.java

@@ -24,9 +24,12 @@ public class TbelCfCtx implements TbelCfObject {
 
     @Getter
     private final Map<String, TbelCfArg> args;
+    @Getter
+    private final long lastTs;
 
-    public TbelCfCtx(Map<String, TbelCfArg> args) {
+    public TbelCfCtx(Map<String, TbelCfArg> args, long lastUpdateTs) {
         this.args = Collections.unmodifiableMap(args);
+        this.lastTs = lastUpdateTs != -1 ? lastUpdateTs : System.currentTimeMillis();
     }
 
     @Override